The present invention relates to a multi-purpose gazing point illuminating device which can change the lighting direction corresponding to the gazing direction of the user. It further relates to a surgical operation illuminating system that uses the same device.
For a light in an operation room of a hospital, a so-called astral lighting system has been used to illuminate the part of operation with high illuminance without casting shadows there.
An astral lighting system is constructed so that many lamps are embedded in a large dish-like base which is suspended from the ceiling of the operation room. Therefore, for its placement, a large room is needed and the ceiling of the operation room must be adequately high. Furthermore, because of its very heavy weight, not only the ceiling but also the whole operation room is required to be structurally strong. As a result, the construction cost of an operation room is high due to this lighting system.
Another problem of the astral lighting system is that it generates a large amount of heat. In a heart operation, however, the temperature of the patient""s body must be kept low. In such case, a high-power cooling system must be provided to overcome the heat caused by the lighting system and lower the body temperature in a short time. This also has increased the construction cost of the operation room.
When an operation is performed, several people including operation doctors and assisting staff stand by the operation bed, as shown in FIG. 11. In a culmination or an important time of an operation, they tend to unconsciously lean forward to gaze the part of operation, so that their heads intercept the light from the astral lighting system 30 to the part of operation, making a shadow on the part.
In a certain kind of operation, an operator needs to look at the part of operation from the side, not from the high as shown in FIG. 11. For example, in an operation for a colon tumor, the operator needs to look at the anal from side. In this case, in addition to the astral lighting system on the ceiling, another side lighting system is necessary to directly illuminate the part. Since it is normally impossible to use a side lamp as large as the astral lighting system on the ceiling, the operator is sometimes required to take a clumsy or unnatural position for avoiding his own shadow cast on the part of operation.
It has already been proposed to fix a lamp to the operator""s head. Or a device has been proposed in which an end of an optical fiber bundle is fixed to the operator""s head and a beam of light from a remote light source is transmitted therethrough. Since, in these cases, the lamp or the light emitting end of the fiber bundle is fixed to the operator""s head, he/she must change the position of his/her head when he/she wants to change the illuminating direction. When an operation takes a long time, the operator needs to change his/her head position frequently or needs to take and keep clumsy postures for a certain period of time, which causes an excessive fatigue in his/her neck or shoulder.
Besides the above-mentioned surgical operation, it is also convenient if, in the case of a home medical care or a nursing care, the lighting direction can be changed freely corresponding to the part to be cared. Especially in the home medical care case, an easy and portable device that can illuminate a necessary point is required because conventional lighting systems are hard to carry around.
The present invention is achieved in this respect placing its primary object to provide a gazing point illuminating device that can light in a desired direction easily and illuminate an object point without making a shadow. Another object is to provide a portable gazing point illuminating device for illuminating a desired point without requiring a clumsy posture of the user. Preferably it can be used in a surgical operation.
According to the present invention, a gazing point illuminating device is provided with: a light source; a direction changing mechanism for changing the lighting direction of the light source; a gazing direction detector for detecting the direction of the user""s gazing line; and a controller for changing the lighting direction corresponding to the detected gazing direction.
In the present invention, the user""s gazing direction is detected and the lighting direction of the light source is changed corresponding to the detected gazing direction, so that the gazing point of the user is always illuminated automatically. When the device is used in a surgical operation, for example, the operating doctor need not take a clumsy posture as was conventionally required, and the part of operation can be illuminated assuredly and safely. When the device is used in the case of a home medical care or a nursing care, the part to be cared can be illuminated according to the doctor""s or care-taker""s gazing direction.
In a style of the present invention, an EL (Electro-Luminescence) panel may be used as the light source. An EL panel is a lighting device using a thin-film electroluminescent element. There are two types in the EL panels: an inorganic EL type and an organic EL type. The inorganic EL type includes those using manganese added zinc sulfide (ZnS:Mn), terbium added zinc sulfide (ZnS:Tb), cerium added strontium sulfide (SrS:Ce), cerium added strontium thiogallate (SrGa2S4:Ce), etc. The organic EL type includes those using tetraphenyl-diamine derivatives (TPD), polyvinyl-carbazole (PVK), aluminum-quinolinol complex (Alq3), distyryl-biphenyl derivatives (DPVBi), etc. The EL panel used in the present invention may be shaped flat or concave against the lighting direction. When it is shaped concave so that the light from the whole EL panel is converged to an object point or object area, the illuminating efficiency is very high.
In another style of the present invention, the light source may be an LED (Light Emitting Diode) panel in which an LED or a plurality of LEDs are arranged on a base board. The number of LEDs on an LED panel depends on the strength of the LED used and the brightness needed by the illuminating device using the LED panel. When a plurality of LEDs are used, they may be arranged on the base board one-dimensionally (straight or curve) or two-dimensionally. The base board can be flat or concave against the lighting direction, as described above for the EL panel.
An LED has a high energy-converting efficiency. Compared to conventional incandescent lamps, its energy consumption is greatly reduced and the heat generation is thus minimized. When it is used in a surgical operation where the part of operation needs to be cooled, the operation can be performed without a powerful cooling system.
An LED has other great advantages of longlife and lightweight. The illuminating device of the present invention using an LED panel also has the same advantages over conventional illuminating devices. When the gazing point illuminating device of the present invention is used in a surgical operation, the cost can be greatly reduced compared to the conventional astral lighting system which claims a large construction cost and requires a costly cooling system.
When an LED panel is used in the present invention, white LED or LEDs may be used. In this way, the illuminating device of the present invention realizes an energy-saving, lightweight and longlife white light source which can replace conventional incandescent lamps or fluorescent lamps.
White LEDs can be fabricated either by the combination of LEDs emitting at blue, green and red spectral range, or by the combination of blue LEDs and phosphors. Latter type of white LEDs, for example, consist of InGaN-based LED and YAG-phosphor, whose spectra are composed of two emission bands, where the blue band peaking at 460 nm is the emission from InGaN quantum-well-active layers, and the broad yellow band at 560 nm is the one from YAG phosphor.
When an LED panel is used in the present invention, the LED panel may be composed of a set or a plurality of sets consisting of a red (R) LED, a green (G) LED and a (B) LED. By presetting the respective lighting strengths of the R, G and B LEDs, light of a desired color can be obtained. When it is used for a surgical operation or for a home medical care purpose, the strengths of the three primary colors can be preset so that the color of the skin or blood looks natural.
When the LEDs are used in a medical field, the intensity distribution in the red spectral region is very important to render inherent color of raw flesh such as skin, blood, fat tissue and internal organs. This can be achieved by adding red LEDs in the array of white LEDs or white LED chips.
When an LED panel is used in the present invention, the LED panel may include an ultraviolet LED or LEDs. In this way, the ultraviolet light from the illuminating device of the present invention excites a fluorescent signing attached to an object beforehand. When it is used in a surgical operation, morbid parts, such as a tumor, attached by a fluorescent signing can be made exclusively visible. The ultraviolet LEDs may be used alone, with white LEDs or with the RGB LEDs in the LED panel. When LEDs of different kinds are used in combination, all kinds of LEDs may be lit simultaneously, or they may be switched depending on the situation or purpose of illumination.
When an LED panel is used in the present invention, LEDs placed on the base board may be packaged type LEDs or chip type LEDs. An LED itself is as small as 0.5 mm or less. For general use of an LED as a light source, for the purpose of protecting the LED, safety, and convenience of handling, an LED is normally packaged in a cannonball-shaped transparent plastic case of about several millimeters with two lead wires drawn outside. For the gazing point illuminating device of the present invention, such individually packaged LEDs may be used, or alternatively, the chip type LEDs may be used. When the chip type LEDs are used, the size and area of the LED panel can be far smaller than that using individually packaged LEDs for the same light emitting strength. This leads to a smaller light source and thus to a far smaller, lightweight gazing point illuminating device.
The illuminating device of the present invention may include a dimming controller for changing the lighting strength of the light source, whereby the gazing object can be illuminated at an arbitrary illuminance. When the light source includes LEDs of various colors (including the case where ultraviolet LEDs are included), it is preferable to control the lighting strengths of respective colors. When, for example, LEDs of the three primary colors are used, a color controller including R-, G- and B-dimming controllers for the respective colors can change the color of the light arbitrarily. If the gazing point illuminating device is used in a surgical operation or in a home medical care, the illuminance and the color can be changed easily as the operator desires. In some important cases, during a surgical operation, a slight color change of the light from the gazing point illuminating device will render clear difference in color of two parts showing similar colors otherwise.
The dimming control of the LEDs can be effected by a knob or the like. Alternatively, it may be effected by a voice recognition device which responds to the user""s voice of verbal order, such as xe2x80x9conxe2x80x9d, xe2x80x9coffxe2x80x9d, xe2x80x9clight upxe2x80x9d or xe2x80x9clight downxe2x80x9d.
In an example of the present invention, the gazing direction detector determines the gazing direction of an eye by detecting a reflection of light projected to an eyeball. In one method, the gazing direction is detected from the distribution of the light reflected by the surface of the eyeball. In another method, a beam of light is projected to an eyeball and the direction of the reflected beam is detected.
In the present invention, the direction changing mechanism may change the lighting direction by tilting the light source vertically and/or horizontally. In this way, the lighting direction can be changed according to the gazing direction.
Alternatively, in the present invention, the direction changing mechanism may include a lens for refracting the light from the light source. The lens is tilted vertically and/or horizontally so that, as described above, the lighting direction can be changed corresponding to the gazing direction.
The gazing point illuminating device of the present invention may be attached to the user""s body such as chest or abdomen, or it may be settled at a certain place of a room. It is also possible that the gazing point illuminating device of the present invention is attached to goggles or eyeglasses. When the goggles or eyeglasses according to the present invention are worn by a user, the user""s shadow will never be cast on the gazing point. This is especially suited for use in a surgical operation. Besides the normal function of goggles to prevent blotting of blood or other stains on the wearer""s eyes, they assure clear illumination of the part of operation without demanding a clumsy posture of the operator during an operation. As several people including the operator and the staff gaze the part of operation, the part is illuminated by the goggles of the people from diverse directions so that the illuminance is stronger and shadowing is more effectively avoided. Further advantage is that the goggles or eyeglasses are portable, which enables them to be easily used in home medical care or other field medical or nursing care. Conventional lighting devices could not have done it.
In another style of the present invention, two sets of light sources are provided corresponding to the left and right eyes. In this case, the gazing direction detectors detect the gazing directions of the left and right eyes independently, and the controller control the direction changing mechanism to change respective light sources"" lighting directions corresponding to the detected left and right gazing directions. Since normally the left and right eyes"" gazing lines cross at the gazing object, a greater illuminance and shadow-free illumination is obtained at the gazing object. As far as two sets are controlled as above, more than two light sources may be employed, of course.
The two light sources may be placed at the left and right ends of the front face of goggles. This style neatly utilizes the free space of the far ends of the goggles.
In this case, the gazing direction detector may determine the gazing direction by detecting the point on a piece of eyeshield of the goggles or on a piece of glass of the eyeglasses where the gazing line penetrates.
For example, the whole area of a piece of eyeshield or a piece of glass is divided into a plurality of sub-areas. Correspondingly, a plurality of lighting directions are predetermined for the light source. When one of the sub-area is determined where the gazing line of the eye penetrates, the controller brings the lighting direction of the light source to the direction corresponding to the detected sub-area. This is a rather simple way of detecting the gazing direction.
The surgical operation illuminating system of the present invention uses the gazing point illuminating device as described above, which detects the operator""s gazing direction and change the lighting direction of the light source accordingly. In this system, the operator need not take a clumsy posture during an operation. The light source is always directed to the gazing object while the operator takes a variety of postures necessary for the operation. The accuracy of the operation will be improved greatly.
Above described gazing point illuminating devices are constructed so that they detect the user""s gazing direction and change the lighting direction accordingly. When, however, the light source is attached to goggles or eyeglasses, the lighting direction normally accords with the gazing direction of the wearer, unless the wearer intentionally averts the eyes.
There have been so far many proposals for goggles or eyeglasses with a lamp or lamps. For example, Japanese Unexamined Utility Model Publication Nos. S56-156022 and S57-22720 disclose eyeglasses with a lamp at the center of the upper frame. Japanese Unexamined Utility Model Publication No. H6-7702 discloses eyeglasses for medical use to which an ordinary lamp is placed at the upper frame (paragraph [0021] of the publication). Japanese Utility Model Registration No. 3049423 discloses goggles for otolaryngologists which have lamps at the lower-left corner of the frame besides at the upper center. Japanese Unexamined Patent Publication No. 2000-39595 discloses eyeglasses with ordinary lamps on both temples.
However, none of them have been put into practical use. This can be ascribed to inadequate consideration into a proper selection of the light source and its location.
In the present invention, an LED panel or an EL panel, which are very compact and lightweight, are used for the light source. In case of an LED panel including a plurality of LEDs, the LEDs are arrayed one-dimensionally (straight or curve) or two-dimensionally. In case of an EL panel, an appropriate shape is cut out to fit the goggles or eyeglasses. The LEDs or EL panel are so lightweight that the goggles or eyeglasses according to the present invention weigh almost the same as ordinary ones without such a light source. Thus a practical gazing point illuminating device is realized by the present invention without causing fatigue to the wearer after wearing a long time. Among them, an LED panel is preferable because of its strong light, high efficiency and long life.
The LED panel or panels, or EL panel or panels, may be placed at the upper frame or lower frame of the goggles or eyeglasses. It is more preferable to attach them at the left and right ends of the front face of the goggles because they make a larger cross angle of the lighting directions which provides a better shadow-free illumination.
An LED has a high energy converting efficiency. When an LED or LEDs are used as the light source, heat generation is greatly reduced and the energy consumption is saved. The cost for a surgical operation illuminating system can be greatly reduced since the conventional large astral lighting system and a large cooling system are no more necessary.
For the portable use of LED-goggles, white LEDs can be driven, for example, by rechargeable Li-ion battery whose output voltage (current) can be controlled by a DCxe2x80x94DC converter.
According to the present invention, LEDs of the three primary colors, red, green and blue, are combined to provide light of a desired color. This enables a natural color appearance of the skin or blood. By using ultraviolet LED or LEDs, the application field is greatly expanded. For example, a fluorescent signing is put on a morbid part such as a tumor first in a preparatory examination. Then the morbid part can be recognized clearly during a subsequent operation.
In many road signs, fluorescent paint is used. The goggles or eyeglasses of the present invention using ultraviolet LED or LEDs can be preferably worn by a person walking or riding a bicycle at night. The fluorescent road signs can be recognized very obviously, which contributes greatly to the traffic safety.
Another useful situation is a night fishing. It is usually very difficult to perceive a motion of the float in a night fishing. In this case, similarly, the float can be made more clearly visible by making the float of fluorescent material or painting it with fluorescent paint, and then wearing goggles or eyeglasses using ultraviolet LEDs.